Answer:
To make an oral presentation more effective he could have used supportive material, maintain eye contact with his classmates, speak clearly.
Step-by-step explanation:
-The use of supportive material is something very useful when you are trying to give an oral presentation. You can use many tools like posters, some audiovisual material like: a short video, or you can use a program like power point.
-Try to maintain eye contact is something really important when you give an oral presentation. People will see you as a secure person and they will pay attention to what you are explaining.
-Speak clearly: you can memorize key phrases in order to repeat it in your oral presentation. Do not memorize everything. Try to understand everything you want to say so in that way you can use your own words in case you forget something.